The subject matter disclosed herein relates generally to imaging systems, and more particularly to an apparatus and method for motion-correcting medical images.
Multi-modality imaging systems exist that scan using different modalities, for example, Computed Tomography (CT), Magnetic Resonance Imaging (MM), Positron Emission Tomography (PET), and Single Photon Emission Computed Tomography (SPECT). During operation, the image quality of the conventional imaging systems may be affected by the motion of the object being imaged. In particular, motion of the imaged object can degrade the image quality. More specifically, image artifacts are produced by movement of the object during image acquisition. Respiratory motion is a common source of involuntary motion in mammals (e.g., people and animals) encountered in medical imaging systems. The respiratory motion may lead to errors during image review, such as when a physician is determining the size of a lesion, determining the location of the lesion, or quantifying the lesion.
One known method for reducing the imaging artifacts is to sort the image data into a plurality of gates based on a respiratory signal. One of the gates is then selected as the reference gate and the remaining gates are then registered to the reference gate. For example, the reference gate selected typically includes information that is collected at the end of the patient's breathing cycle. However, the reference gate having information collected at the end of the patient's breathing cycle may not include optimal information for registering the remaining gates. For example, the reference gate having information collected at the end of the patient's breathing cycle may not include a fewer number of pixels or pixels having a reduced pixel intensity. Thus, when the remaining gates are registered with the reference gate, the quality of the resultant image may be reduced.